I recently took a Ukrainian taxi from the airport to my hotel. The fare should have been $20. The cab driver was adamant that I pay $30. When I finally paid him $30, the driver gave me a receipt with a wink. He'd made it out for $40.
The driver got a cut by overcharging me, and assumed that I would take a cut by overcharging NPR (which I did not).
In Ukraine, corruption is a daily fact of life. It reaches into big business, law enforcement, education and even the smallest transactions between people on the street.